title: A cytochrome P450 regulates a domestication trait in cultivated tomato.
abstract: Domestication of crop plants had effects on human lifestyle and agriculture. However, little is known about the underlying molecular mechanisms accompanying the changes in fruit appearance as a consequence of selection by early farmers. We report the fine mapping and cloning of a tomato (Solanum lycopersicum) fruit mass gene encoding the ortholog of KLUH, SlKLUH, a P450 enzyme of the CYP78A subfamily. The increase in fruit mass is predominantly the result of enlarged pericarp and septum tissues caused by increased cell number in the large fruited lines. SlKLUH also modulates plant architecture by regulating number and length of the side shoots, and ripening time, and these effects are particularly strong in plants that transgenically down-regulate SlKLUH expression carrying fruits of a dramatically reduced mass. Association mapping followed by segregation analyses revealed that a single nucleotide polymorphism in the promoter of the gene is highly associated with fruit mass. This single polymorphism may potentially underlie a regulatory mutation resulting in increased SlKLUH expression concomitant with increased fruit mass. Our findings suggest that the allele giving rise to large fruit arose in the early domesticates of tomato and becoming progressively more abundant upon further selections. We also detected association of fruit weight with CaKLUH in chile pepper (Capsicum annuum) suggesting that selection of the orthologous gene may have occurred independently in a separate domestication event. Altogether, our findings shed light on the molecular basis of fruit mass, a key domestication trait in tomato and other fruit and vegetable crops.
authors.affiliation: Department of Horticulture and Crop Science, The Ohio State University/Ohio Agricultural Research and Development Center, Wooster, OH 44691.
authors.forename: Manohar
authors.initials: M
authors.lastname: Chakrabarti
authors.forename: Na
authors.initials: N
authors.lastname: Zhang
authors.forename: Christopher
authors.initials: C
authors.lastname: Sauvage
authors.forename: Stéphane
authors.initials: S
authors.lastname: Muños
authors.forename: Jose
authors.initials: J
authors.lastname: Blanca
authors.forename: Joaquin
authors.initials: J
authors.lastname: Cañizares
authors.forename: Maria Jose
authors.initials: MJ
authors.lastname: Diez
authors.forename: Rhiannon
authors.initials: R
authors.lastname: Schneider
authors.forename: Michael
authors.initials: M
authors.lastname: Mazourek
authors.forename: Jammi
authors.initials: J
authors.lastname: McClead
authors.forename: Mathilde
authors.initials: M
authors.lastname: Causse
authors.forename: Esther
authors.initials: E
authors.lastname: van der Knaap
mesh_terms: D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis* / Q000235:genetics; D015536:Down-Regulation / Q000502:physiology; D005638:Fruit / Q000201:enzymology* / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D006801:Humans; D018551:Solanum lycopersicum / Q000201:enzymology* / Q000235:genetics; D010940:Plant Proteins / Q000096:biosynthesis* / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci / Q000502:physiology*
chemical_list: D010940:Plant Proteins; D003577:Cytochrome P-450 Enzyme System